Remote-controlled oil well pipe shear and shutoff apparatus

ABSTRACT

In an offshore oil well production system including a surface platform, a submerged wellhead, and a pipe string interconnecting the wellhead and platform, the provision of a pipe shear and shutoff apparatus between the platform and wellhead having a housing with a throughbore with an enlarged intermediate chamber and end bores for receiving a section of the pipe and means within the apparatus for shearing the pipe and closing the fluid passage through the apparatus when the pipe is severed, means for selective actuation of the apparatus and remote control means for the actuating means which is operative at a remote location from the wellhead notwithstanding the loss of physical connection between the platform and wellhead through the pipe string, such as when the pipe string is ruptured.

United States Patent [72] Inventors Valdek J. Orund Anaheim; Edward T.Cugini, Brea, both of, Calif. [2]] Appl. No 806,516 [22] Filed Mar.12,1969 [45] Patented July 6, 1971 [73] Assignee Shaffer Tool WorksBrea, Calif.

[54] REMOTE-CONTROLLED OIL WELL PIPE SHEAR AND SHUTOFF APPARATUS 10Claims, 9 Drawing Figs.

[52] U.S.Cl 166/55, 166/5 [51] Int. Cl E21b29/00 [50] FieldofSeai-chl66/.5,.6, 55

[56] References Cited UNITED STATES PATENTS 1,851,894 3/1932 Ciough166/55 2,919,111 12/1959 Nicolson 166/55 an, r 82" "'88,

Primary Examiner-Marvin A. Champion Assistant ExaminerRichard E. FavreauAttorney-Miketta, Glenny, Poms 8!. Smith ABSTRACT: In an offshore oilwell production system includ' ing a surface platform, a submergedwellhead, and a pipe string interconnecting the wellhead and platform,the provision of a pipe shear and shutoff apparatus between the platformand wellhead having a housing with a throughbore with an enlargedintermediate chamber and end bores for receiving a section of the pipeand means within the apparatus for shearing the pipe and closing thefluid passage through the apparatus when the pipe is severed, means forselective actuation of the apparatus and remote control means for theactuating means which is operative at a remote location from thewellhead notwithstanding the loss of physical connection between theplatform and wellhead through the pipe string, such as when the pipestring is ruptured.

56 53 71 f5? 52 1 53 d;11 ="-i5g 5 42 l 4/ 65k? 54a 12 3O 54 PATENIEDJUL 6 1971 SHEET 2 BF 3 [NI EN TOPS V2.4. DEK J dew/v0 .Eawpeo If Cue/1wPATENTEDJUL slsn 3.590.920

snm 3 OF 3 WLpEK J flea/v0 Eon 4 20 Z Cue/M I524 lull-Ill...

m m a I j M i REMOTE-CONTROLLED OIL WELL PIPE SHEAR AND SHUTOFFAPPARATUS The present invention relates to an apparatus for use inconnection with oil well offshore production systems wherein a surfaceplatform is stationed with respect to a wellhead and is interconnectedwith the wellhead through at least one pipe string. Generally, theplatform or floating vessel is maintained in its relative position tothe wellhead by suitably securing the floating vessel to the floor ofthe ocean or sea through mooring lines.

In the above-described system, as well as in various other types ofoffshore oil well production systems, there may be provided an apparatusfor shearing the pipe string and shutting off the fluid passage in theevent of rupture of the pipe string so as to prevent blowout of thewell. In operation, it is necessary to actuate such apparatus so as toperform the shearing and shutoff functions. Such operation may bemanual, such as by sending down a diver, but the disadvantages of suchoperation are apparent. In the prior art, the operation of shear andshutoff apparatus has been controlled from the surface platform.However, the defect in such prior-art systems is that ifthe surfaceplatform moves relative to the wellhead so as to rupture the pipestring, it will also likely rupture any other physical meansinterconnecting the platform and the apparatus to be controlled. Forexample, if the anchor lines ofthe surface platform are severed byanother vessel, or break because of heavy seas, there is no longer anyphysical connection between the surface platform and the apparatus.

In the pipe shear and shutoff apparatus known to the prior art, there isalso the difficulty of reliably assuring that the fluid flow passagewill be completely shut off because of the possibility that the pipewill not be properly severed. In other words, in some prior-artapparatus, the shearing means may result in crushing or deforming of thepipe which would interfere with the effective shutoff of the flowpassage.

Accordingly, it is a general object of the present invention to providea remote-controlled oil well pipe shear and shutoff apparatus thatavoids all of the foregoing disadvantages of similar types of apparatusand offshore oil well production systems used heretofore.

It is another object of the present invention to provide an offshore oilwell production system including a surface platform, a submergedwellhead, an interconnecting pipe string, a submerged pipe shear andshutoff apparatus, with means for remotely controlling the actuation ofthe apparatus so that the fluid flow passage may be shut off in theevent of pipe string rupture and movement of the platform relative tothe wellhead.

It is still another object of the present invention to provide anoffshore oil well production system of the above-described type, whereinthe remote control means may include signal transmitting and receivingapparatus carried by the platform and the pipe shear and shutoffapparatus for selective operation by an operator aboard the platform.

It is yet another object of the present invention to provide an offshoreoil well production system of the above-described type wherein theremote control means may include fixed length means physicallyinterconnecting the platform and wellhead when the platform is in apreselected location relative to the wellhead which is ruptured when theplatform is moved from such preselected location so as to automaticallyactuate the pipe shear and shutoff apparatus.

One more object of the present invention is to provide a submerged pipeshear and shutoff apparatus wherein a pipe string may be simultaneouslysheared and shut off and wherein the shutoff means is maintained insealing relation to prevent fluid passage flow.

It is yet one more object of the present invention to provide anapparatus of the last-described type wherein the seal is maintainedwithout physical contact between a surface platform and the wellheadwhich was interconnected by the pipe string prior to rupture.

Other objects and advantages of this invention will be readily apparentfrom the following description when considered in connection with theappended drawings.

IN THE DRAWINGS FIG. I is a schematic view of an exemplary offshore oilwell production system including the present invention;

FIG. 2 is a detailed view of the apparatus shown in FIG. 1 illustratingcomponents of the system schematically;

FIG. 3 is a detailed view as in FIG. 2 showing alternate components foruse in the system;

FIG. 4 is a side sectional view of the apparatus shown in FIGS. 2 and 3;

FIG. 5 is a side sectional view as in FIG. 4 showing apparatus inshutoff position;

FIG. 6 is a sectional view taken along the plane VI-VI of FIG. 4;

FIG. 7 is a sectional view taken along the plane VII-VII of FIG. 4;

FIG. 8 is a sectional view taken along the plane VIIIVIII of FIG. 4; and

FIG. 9 is a sectional view taken along the plane lX-IX of FIG. 5.

Referring now to FIGS. 1 through 3, there is shown in FIG. 1 an offshoreoil well production system generally comprising a surface platform orvessel 20, a wellhead indicated generally at 21, and a production lineor pipe string generally indicated at 22. The platform 20 may be fixedor supported by the floor of the body of water, or may be a floatingvessel such as that illustrated at 20. The wellhead 21 is submerged orundersea and is mounted to the floor of the sea in a manner well knownin the art. While a plurality of production lines or pipe strings mayinterconnect the wellhead and surface platform, there is' shown forpurposes of illustration a single pipe string 22 comprising a pluralityof pipe sections which may extend generally vertically from the wellheadto the platform.

The platform 20 may be secured in its relation or position to thewellhead by means of anchor lines 23 which may be connected to asubsurface buoy 24 connected through a cable 25 to an anchor 26 on theocean floor. Obviously, other means for maintaining the floatingplatform 20 in relation to the wellhead 21 may be provided as are wellknown in the art.

In the present invention, the offshore oil well production system isalso provided with a submerged pipe shear and shutoff apparatusgenerally indicated at 30, means for selective actuation of theapparatus indicated generally at 80, and remote control means generallyindicated at 110. The pipe shear and shutoff apparatus is submerged andmay be mounted adjacent the wellhead between the platform and thewellhead. The means 60 for selective actuation of the apparatus may becarried by such apparatus as in the exemplary embodiment.

Remote control means, indicated generally at 110, in the exemplaryembodiment illustrated in FIG. 2, may comprise a signal-transmittingmeans 111, such as a radio transmitter, carried by floating platform 20.The remote control means also includes signal-receiving means 112, asseen in FIG. 2, carried by means for selective actuation of pipe shearand shutoff apparatus 30. There is shown a second exemplary embodimentof means for remote control of the apparatus-actuating means whichcomprises a fixed length physical means such as a fluid pressure line115 in operative communication with the means 80 when the pipe string 22is intact.

In operation, each of the above-described remote control meansautomatically renders the actuating means operative, or maintainsoperative connection between the apparatus and surface platform, uponmovement of the platform from its preselected position relative to thewellhead. In the first embodiment, rupture of the pipe string 22 whichcould occur when platform 20 has broken away from its anchor line 23,severs all physical connection between the platform 20 and the pipeshear and shutoff apparatus 30. However, an operator aboard floatingvessel 20 may manually transmit a signal from transmitting means 111 tosignal-receiving means 112 so as to render actuating means 80 operativethereby shearing pipe string 22 and providing fluid flow shutoff. In thesecond embodiment, movement of the surface platform 20 so as to rupturepipe string 22 will simultaneously cause rupture of fixed length fluidpressure line 115 opening such line to ambient pressure which willrender the actuating means operative so as to shear and shut off pipestring 22.

The submerged pipe shear and shutoff apparatus 30 of the presentinvention generally comprises a housing 32, carrier means indicatedgenerally at 40, pipe-shearing means indicated generally at 50, closingmeans indicated generally at 60, means axially urging a shutoff pluginto sealing relation indicated generally at 65, and the actuating meansindicated generally at 80.

Referring now to FIGS. 4 through 9, there is shown an exemplaryembodiment of a pipe shear and shutoff apparatus in accordance with thepresent invention wherein the housing 32 includes a through bore 33which defines a work chamber 34 and top and bottom end bores 35, 36respectively. Chamber 34 is intermediate the end bores 35, 36 and isenlarged and disposed laterally of the longitudinal axis of the pipepassing through housing 32 and indicated at P. Pipe P comprises a firstpipe section P1 connected to the platform 20 and a second pipe sectionP2 connected to the wellhead 21. The intermediate enlarged chamber 34may also include a second laterally disposed portion indicated at 34afor receiving the cutting blade and any portions of the pipe which maybe crushed after the shearing operation is complete.

Carrier means 40 is slidably mounted for movement transverse to the axisof pipe P and is normally disposed in a zone to one side of the axis ofpipe P. In the exemplary embodiment, such carrier means may comprisecarrier member 41 having a downwardly directed opening 42 for receivingthe actuating rod of the actuating means described hereinafter. Carriermember 41 has a generally cylindrical opening 43 for receiv ing ashutoff plug and has parallel sidewalls 44, 45 as seen best in FIG. 9.The carrier member 41 is slidably supported on longitudinally extendingtracks 46, 47 disposed transversely to the axis of pipe P and withinchamber 34 and preferably integral with housing 32, as seen in FIG. 9.Housing 32 also includes guideways 37, 38 integral with the verticalwalls adjacent the tracks 46, 47, respectively, and extendinglongitudinally parallel with the tracks on opposite sides of carriermember 41 and in sliding engagement with carrier member sidewalls 44, 45to guide transverse movement of the carrier member.

The pipe shear and shutoff apparatus 30 also includes pipeshearing meansindicated generally at 50 which comprises blade means 51 and anvil means55. Blade means 51, in the exemplary embodiment, is carried by carriermember 41 for movement transverse to pipe P. The blade means comprises ablade or cutting edge 52 fixedly mounted on the forward end of carriermember 41 with fasteners 53. The cutting edge 52 has a width greaterthan the diameter of pipe P and has an upper edge in the same horizontalplane as the upper surface of the carrier member 41, as seen in FIGS. 4and 5. In the preferred embodiment, the cutting edge 52 is straight andis angularly oriented with respect to the direction of movement.

The anvil means in the exemplary embodiment is fixedly mounted in thehousing 32 and comprises an annular member 56 of hardened steel retainedin the housing at the upper surface of the chamber by studs 57. Annularanvil member 56 is mounted at the periphery of through bore portion 35and is sealed within the chamber housing by means of annular sealingring 58. The lower plane of anvil member 56 is coplanar with the upperplane of carrier member 41 and cutting edge 52 so as to define a shearplane.

The pipe shear and shutoff apparatus 30 also includes closing means 60for preventing fluid passage through housing 32 when pipe P has beensevered. In the exemplary embodiment, such closing means comprises ashutoff plug 61 carried by carrier member 41 in opening 43 fortransverse movement into an operative position (as seen in FIG. 5)axially aligned with through bore 33. Shutoff plug 61 comprises asubstantially cylindrical, solid, metallic body 62 having an axissubstantially parallel to the axis of pipe P. The shutoff plug 61carries an annular sealing member 63 on the peripheral edge of the uppersurface for sealing engagement with anvil member 56 when the shutoffplug is in the operative position.

Means 65 for axially urging the shutoff plug 61 is provided in apparatus30 and in the exemplary embodiment comprises ramp or cam means 66carried by housing 32 in the path of carrier member 41. Ramp means 66includes a pair of ramp members 67, 68 positioned on opposite sides ofthrough bore 35 within chamber 34 and integral with tracks 46, 47, asseen best in FIG. 9. The means for axially urging the shutoff plug intosealing relation with the anvil member 56 mounted in housing 32 alsoincludes ramp surfaces 69, 70 on the lower side of shutoff plug body 62defined by cutout portions thereof. The ramp surfaces 69, 70 have thesame slope and are complementary with the ramp members 67, 68.Preferably, the ramp members and ramp surfaces have a slope so as toprovide substantial friction through the mctal-to-metal contact thereofso as to maintain the shutoff plug and anvil member in sealing relation.

The pipe shear and shutoff apparatus 30 includes actuating means whichin the exemplary embodiment comprises an actuator housing 81 defining acylindrical chamber 82 open at one end and sealed by an end plate 83through a plurality of fasteners 84. The opposite end of housing 81 issecured through studs and nuts 85 to the end of housing 32 of theapparatus. The engaging wall 86 of actuator housing 81 is provided withan opening 87 for receiving the actuator member 88 of a piston 89slidably mounted in chamber 82. Piston 89 carries annular sealingmembers 90 while end wall 86 of housing 81 carries sealing members 91for sealing engagement with actuator rod 88. The actuating means alsocomprises a highpressure fluid source 92 as seen in FIGS. 2 and 3, influid communication with piston chamber 82 through a conduit 93, valve94, and conduits 95, 96.

In the embodiment illustrated in FIG. 2, the valve 94 may be a simplesingle-gate valve controlled by signal receiving means 112 so as toallow the high-pressure gas to flow from source 92 through the valvethrough conduit 95 thereby moving piston 89 and carrier member 41 to theright, as viewed in FIGS. 4 and 5. Conduit 96 is provided for relief andfor returning the carrier means to the inoperative position after theshear and shutoff apparatus has been used. In the embodiment illustratedin FIG. 3, the valve 94 is actuated by rupture of the fluid pressureline opening such line to ambient pressure so that the high-pressure gassource may open the gate allowing the high-pressure gas to pass throughconduit 95 and to move piston 89 as previously described.

In operation, when the carrier means is moved transverse to the pipe,the blade or cutting edge 52 severs the pipe P into portions P, and PSimultaneously the shutoff plug 61 is moved into axial alignment withthe through bore 33 and pipe sections P, and P and is axially urgedthrough ramp members 67, 68 and ramp surfaces 69, 70 into sealingrelation with anvil member 56 so as to preventfluid flow through theapparatus thereby preventing blowout of the well. The shutoff plug ismaintained in the sealing relation by virtue of the low slope and highfriction between the ramp members and ramp surfaces which maintains theshutoff plug and anvil member in contact. Moreover, it is an importantfeature of this invention that the shutoff plug is maintained in sealingrelation by the differential in pressure across the shutoff plug.Specifically, if pipe section P is connected to the wellhead whereaspipe P, is connected to the platform and is the pipe that will beruptured, the pressure acting on the underside of the shutoff plug willbe the well pressure whereas the pressure acting on the upper surfacewill be ambient pressure. This difference in pressure will tend tomaintain the shutoff plug in sealing relation with the anvil member. s

It is also to be understood that the drill string pipe sectionconnections are not easily severable by the apparatus of the presentinvention, and it is therefore contemplated that a pair of suchapparatus may be employed in spaced relation such that one of suchapparatus will necessarily be positioned on a nonconnection portion ofthe drill string.

It will now be seen that all of the above-mentioned objects areaccomplished by the invention and the preferred embodiment described andillustrated herein. Other modifications and variations of the presentinvention are possible in light of the above teachings and it istherefore to be understood that within the scope of the appended claims,the invention may be practiced otherwise than as specifically described.

We claim:

1. A combination pipe shear and shutoff apparatus for use in welloperations to sever a pipe string and provide immediate complete shutoffin the event of pipe string rupture, comprismg:

a housing defining a work chamber and including a through bore forreceiving a pipe;

carrier means slidably mounted in said work chamber for movementtransverse to said pipe;

pipe-shearing means including blade means carried by said carrier meansto effect cutoff of said pipe;

a shutoff plug carried by said carrier means in a direction transverseto said pipe into an operative position;

means axially urging said shutoff plug into sealing relation with saidhousing through bore when in the operative position; and

actuating means for selective movement of said pipe-shearing blade meansand said shutoff plug.

2. The apparatus of claim 1 wherein said means axially urging saidshutoff plug into sealing relation with said housing through borecomprises ramp means carried by said housing within said work chamber inthe path of slidable movement of said shutoff plug and said plugincludes complementary ramp surfaces whereby transverse sliding movementof said plug into sealing relation with said chamber through bore.

3. The apparatus of claim 1 wherein said actuating means comprises anactuator housing defining a cylinder, a piston slidably mounted in saidcylinder and in operative engagement with said carrier means, ahigh-pressure fluid source in fluid communication with said pistoncylinder, and valve means for selectively controlling fluid flow to andfrom said piston cylinder.

4. The apparatus of claim 1 wherein said pipe-shearing meansadditionally includes annular anvil means fixedly sup ported by saidhousing and at the periphery of said through bore.

5. The apparatus of claim 1 wherein said shutoff plug, after cutoff ofsaid pipe, is in sealing relation with said housing through bore portionreceiving that section of the pipe extending away from a wellhead, theother through bore portion receiving that section of the pipe connectedto the wellhead, whereby said shutoff plug surface in sealing relationis exposed to ambient pressure when said pipe section extending awayfrom the wellhead is ruptured and the opposite surface of said shutoffplug is exposed to well fluid pressure thereby urging said shutoff pluginto further sealing relation with said housing through bore.

6. The apparatus of claim 1 wherein said shutoff plug comprises asubstantially cylindrical solid metallic body having an axissubstantially parallel to the axis of said housing through bore andcarries an annular sealing member for engagement with said annular anvilmeans when said shutoff plug is in the operative position.

7. The apparatus of claim 1 wherein said housing includes longitudinallyextending tracks disposed transversely to said pipe and within said workchamber for slidably supporting said carrier means, and longitudinallyextending guide ways substantially parallel to said tracks and withinsaid chamber dlSJOSCd on op osite sides of said carrier means.

In a corn lnation pipe cutoff and shutoff apparatus for use in welloperations for severing a pipe having a longitudinal axis, thecombination of:

a housing having an internal chamber disposed laterally of said pipeaxis and having a through bore extending along said axis for receiving aportion of said pipe in said chamber;

carrier means guidably mounted within said chamber in a zone transverseto and at one side of said axis for cutting said pipe and sealing saidthrough bore by movement of said carrier means in one direction in saidzone;

said carrier means including a fixed cutting edge and a shutoff plugbehind said fixed cutting edge and movable relative to said carriermeans in the axial direction of said P p and actuating means for saidcarrier means whereby movement of said carrier means in said onedirection is adapted to out said pipe portion within said chamber and toimmediately thereafter move said plug to seal said through bore.

9. An apparatus as stated in claim 8 wherein said internal chamberincludes a chamber portion on the opposite side of said axis forreceiving said fixed cutting edge on said carrier means and the crushedsevered end of said pipe.

10. An apparatus as stated in claim 8 including cam means on saidhousing engageable by said plug during movement of said carrier means tomove said plug into sealing relation with said through bore.

1. A combination pipe shear and shutoff apparatus for use in welloperations to sever a pipe string and provide immediate complete shutoffin the event of pipe string rupture, comprising: a housing defining awork chamber and including a through bore for receiving a pipe; carriermeans slidably mounted in said work chamber for movement transverse tosaid pipe; pipe-shearing means including blade means carried by saidcarrier means to effect cutoff of said pipe; a shutoff plug carried bysaid carrier means in a direction transverse to said pipe into anoperative position; means axially urging said shutoff plug into sealingrelation with said housing through bore when in the operative position;and actuating means for selective movement of said pipe-shearing blademeans and said shutoff plug.
 2. The apparatus of claim 1 wherein saidmeans axially urging said shutoff plug into sealing relation with saidhousing through bore comprises ramp means carried by said housing withinsaid work chamber in the path of slidable movement of said shutoff plugand said plug includes complementary ramp surfaces whereby transversesliding movement of said plug into sealing relation with said chamberthrough bore.
 3. The apparatus of claim 1 wherein said actuating meanscomprises An actuator housing defining a cylinder, a piston slidablymounted in said cylinder and in operative engagement with said carriermeans, a high-pressure fluid source in fluid communication with saidpiston cylinder, and valve means for selectively controlling fluid flowto and from said piston cylinder.
 4. The apparatus of claim 1 whereinsaid pipe-shearing means additionally includes annular anvil meansfixedly supported by said housing and at the periphery of said throughbore.
 5. The apparatus of claim 1 wherein said shutoff plug, aftercutoff of said pipe, is in sealing relation with said housing throughbore portion receiving that section of the pipe extending away from awellhead, the other through bore portion receiving that section of thepipe connected to the wellhead, whereby said shutoff plug surface insealing relation is exposed to ambient pressure when said pipe sectionextending away from the wellhead is ruptured and the opposite surface ofsaid shutoff plug is exposed to well fluid pressure thereby urging saidshutoff plug into further sealing relation with said housing throughbore.
 6. The apparatus of claim 1 wherein said shutoff plug comprises asubstantially cylindrical solid metallic body having an axissubstantially parallel to the axis of said housing through bore andcarries an annular sealing member for engagement with said annular anvilmeans when said shutoff plug is in the operative position.
 7. Theapparatus of claim 1 wherein said housing includes longitudinallyextending tracks disposed transversely to said pipe and within said workchamber for slidably supporting said carrier means, and longitudinallyextending guide ways substantially parallel to said tracks and withinsaid chamber disposed on opposite sides of said carrier means.
 8. In acombination pipe cutoff and shutoff apparatus for use in well operationsfor severing a pipe having a longitudinal axis, the combination of: ahousing having an internal chamber disposed laterally of said pipe axisand having a through bore extending along said axis for receiving aportion of said pipe in said chamber; carrier means guidably mountedwithin said chamber in a zone transverse to and at one side of said axisfor cutting said pipe and sealing said through bore by movement of saidcarrier means in one direction in said zone; said carrier meansincluding a fixed cutting edge and a shutoff plug behind said fixedcutting edge and movable relative to said carrier means in the axialdirection of said pipe; and actuating means for said carrier meanswhereby movement of said carrier means in said one direction is adaptedto cut said pipe portion within said chamber and to immediatelythereafter move said plug to seal said through bore.
 9. An apparatus asstated in claim 8 wherein said internal chamber includes a chamberportion on the opposite side of said axis for receiving said fixedcutting edge on said carrier means and the crushed severed end of saidpipe.
 10. An apparatus as stated in claim 8 including cam means on saidhousing engageable by said plug during movement of said carrier means tomove said plug into sealing relation with said through bore.